﻿/*
 * Copyright (c) 2010 Nicolas George
 * Copyright (c) 2011 Stefano Sabatini
 * Copyright (c) 2014 Andrey Utkin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

 /**
  * @file
  * API example for demuxing, decoding, filtering, encoding and muxing
  * @example transcoding.c
  */

#ifdef _WIN32
extern "C"
{
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/pixdesc.h>
}
#else
#ifdef __cplusplus
extern "C"
{
#endif
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/pixdesc.h>
#ifdef __cplusplus
};
#endif
#endif

#include "transcode.h"

int Transcode::open_input_file(const char* filename){
    int ret;
    unsigned int i;

    ifmt_ctx = NULL;
    if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
        return ret;
    }

    v_stream_index = av_find_best_stream(ifmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
    if (v_stream_index < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find an audio stream in the input file\n");
        return ret;
    }

    if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
        return ret;
    }

    stream_ctx =(StreamContext*) av_mallocz_array(ifmt_ctx->nb_streams, sizeof(*stream_ctx));
    if (!stream_ctx)
        return AVERROR(ENOMEM);

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        AVStream* stream = ifmt_ctx->streams[i];
        const AVCodec* dec = avcodec_find_decoder(stream->codecpar->codec_id);
        AVCodecContext* codec_ctx;
        if (!dec) {
            av_log(NULL, AV_LOG_ERROR, "Failed to find decoder for stream #%u\n", i);
            return AVERROR_DECODER_NOT_FOUND;
        }
        codec_ctx = avcodec_alloc_context3(dec);
        if (!codec_ctx) {
            av_log(NULL, AV_LOG_ERROR, "Failed to allocate the decoder context for stream #%u\n", i);
            return AVERROR(ENOMEM);
        }
        ret = avcodec_parameters_to_context(codec_ctx, stream->codecpar);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Failed to copy decoder parameters to input decoder context "
                "for stream #%u\n", i);
            return ret;
        }
        /* Reencode video & audio and remux subtitles etc. */
        if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
            || codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO)
                codec_ctx->framerate = av_guess_frame_rate(ifmt_ctx, stream, NULL);
            /* Open decoder */
            ret = avcodec_open2(codec_ctx, dec, NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
                return ret;
            }
        }
        stream_ctx[i].dec_ctx = codec_ctx;

        stream_ctx[i].dec_frame = av_frame_alloc();
        if (!stream_ctx[i].dec_frame)
            return AVERROR(ENOMEM);
    }

    av_dump_format(ifmt_ctx, 0, filename, 0);
    return 0;
}

int Transcode::open_output_file(const char* filename)
{
    AVStream* out_stream;
    AVStream* in_stream;
    AVCodecContext* dec_ctx, * enc_ctx;
    const AVCodec* encoder;
    int ret;
    unsigned int i;

    ofmt_ctx = NULL;
    avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
    if (!ofmt_ctx) {
        av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
        return AVERROR_UNKNOWN;
    }

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        if (parameters.video_only && i != v_stream_index)
            continue;
        dec_ctx = stream_ctx[i].dec_ctx;
        in_stream = ifmt_ctx->streams[i];

        out_stream = avformat_new_stream(ofmt_ctx, NULL);
        if (!out_stream) {
            av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
            return AVERROR_UNKNOWN;
        }
        if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
            || dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            /* in this example, we choose transcoding to same codec */
            AVCodecID streamCodec;
            if(parameters.vcodec && dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO){
                encoder = avcodec_find_encoder((AVCodecID)parameters.vcodec);
                streamCodec = (AVCodecID)parameters.vcodec;
            }
            else{
                encoder = avcodec_find_encoder(dec_ctx->codec_id);
                streamCodec = dec_ctx->codec_id;
            }
            if (!encoder) {
                av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
                return AVERROR_INVALIDDATA;
            }
            enc_ctx = avcodec_alloc_context3(encoder);
            if (!enc_ctx) {
                av_log(NULL, AV_LOG_FATAL, "Failed to allocate the encoder context\n");
                return AVERROR(ENOMEM);
            }

            /* In this example, we transcode to same properties (picture size,
             * sample rate etc.). These properties can be changed for output
             * streams easily using filters */
            if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
                enc_ctx->height = parameters.video_height>100? parameters.video_height:dec_ctx->height;
                enc_ctx->width = parameters.video_width > 100 ? parameters.video_width :dec_ctx->width;
                enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
                if (parameters.video_frame_rate > 15) {
                    enc_ctx->sample_aspect_ratio.den = parameters.video_frame_rate;
                    enc_ctx->sample_aspect_ratio.num = 1;
                }
                /* take first format from list of supported formats */
                if (encoder->pix_fmts)
                    enc_ctx->pix_fmt = encoder->pix_fmts[0];
                else
                    enc_ctx->pix_fmt = dec_ctx->pix_fmt;
                /* video time_base can be set to whatever is handy and supported by encoder */
                enc_ctx->time_base = av_inv_q(dec_ctx->framerate);
            }
            else {
                enc_ctx->sample_rate = dec_ctx->sample_rate;
                enc_ctx->channel_layout = dec_ctx->channel_layout;
                enc_ctx->channels = enc_ctx->channel_layout;
                /* take first format from list of supported formats */
                enc_ctx->sample_fmt = encoder->sample_fmts[0];
                enc_ctx->time_base = { 1, enc_ctx->sample_rate };
            }

            if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
                enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

            /* Third parameter can be used to pass settings to encoder */
            ret = avcodec_open2(enc_ctx, encoder, NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
                return ret;
            }
            ret = avcodec_parameters_from_context(out_stream->codecpar, enc_ctx);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Failed to copy encoder parameters to output stream #%u\n", i);
                return ret;
            }

            out_stream->time_base = enc_ctx->time_base;
            stream_ctx[i].enc_ctx = enc_ctx;
        }
        else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
            av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
            return AVERROR_INVALIDDATA;
        }
        else {
            /* if this stream must be remuxed */
            ret = avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Copying parameters for stream #%u failed\n", i);
                return ret;
            }
            out_stream->time_base = in_stream->time_base;
        }

    }
    av_dump_format(ofmt_ctx, 0, filename, 1);

    if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
        ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
            return ret;
        }
    }
    /* init muxer, write output file header */
    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
        return ret;
    }

    return 0;
}

int Transcode::init_filter(FilteringContext* fctx, AVCodecContext* dec_ctx,
    AVCodecContext* enc_ctx, const char* filter_spec)
{
    char args[512];
    int ret = 0;
    const AVFilter* buffersrc = NULL;
    const AVFilter* buffersink = NULL;
    AVFilterContext* buffersrc_ctx = NULL;
    AVFilterContext* buffersink_ctx = NULL;
    AVFilterInOut* outputs = avfilter_inout_alloc();
    AVFilterInOut* inputs = avfilter_inout_alloc();
    AVFilterGraph* filter_graph = avfilter_graph_alloc();

    if (!outputs || !inputs || !filter_graph) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
        buffersrc = avfilter_get_by_name("buffer");
        buffersink = avfilter_get_by_name("buffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        snprintf(args, sizeof(args),
            "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
            dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
            dec_ctx->time_base.num, dec_ctx->time_base.den,
            dec_ctx->sample_aspect_ratio.num,
            dec_ctx->sample_aspect_ratio.den);

        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
            args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
            NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
            (uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
            AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
            goto end;
        }
    }
    else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
        buffersrc = avfilter_get_by_name("abuffer");
        buffersink = avfilter_get_by_name("abuffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        if (!dec_ctx->channel_layout)
            dec_ctx->channel_layout = dec_ctx->channels;
        snprintf(args, sizeof(args),
            "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%016lx",
            dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
            av_get_sample_fmt_name(dec_ctx->sample_fmt),
            dec_ctx->channel_layout);
        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
            args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
            NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
            (uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
            AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
            (uint8_t*)&enc_ctx->channel_layout,
            sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
            (uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
            AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
            goto end;
        }
    }
    else {
        ret = AVERROR_UNKNOWN;
        goto end;
    }

    /* Endpoints for the filter graph. */
    outputs->name = av_strdup("in");
    outputs->filter_ctx = buffersrc_ctx;
    outputs->pad_idx = 0;
    outputs->next = NULL;

    inputs->name = av_strdup("out");
    inputs->filter_ctx = buffersink_ctx;
    inputs->pad_idx = 0;
    inputs->next = NULL;

    if (!outputs->name || !inputs->name) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
        &inputs, &outputs, NULL)) < 0)
        goto end;

    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
        goto end;

    /* Fill FilteringContext */
    fctx->buffersrc_ctx = buffersrc_ctx;
    fctx->buffersink_ctx = buffersink_ctx;
    fctx->filter_graph = filter_graph;

end:
    avfilter_inout_free(&inputs);
    avfilter_inout_free(&outputs);

    return ret;
}

int Transcode::init_filters(void)
{
    const char* filter_spec;
    unsigned int i;
    int ret;
    filter_ctx = (FilteringContext*)av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
    if (!filter_ctx)
        return AVERROR(ENOMEM);

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        filter_ctx[i].buffersrc_ctx = NULL;
        filter_ctx[i].buffersink_ctx = NULL;
        filter_ctx[i].filter_graph = NULL;

        AVCodecContext* encode_ctx = stream_ctx[i].enc_ctx;
        AVCodecContext* decode_ctx = stream_ctx[i].dec_ctx;
        if (!(encode_ctx&& decode_ctx))//没有创建输入流或输出流编码器
            continue;
        /*only apply filters to video or audio streams.*/
        if (!(ifmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO
            || ifmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO))
            continue;

        if (ifmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
            filter_spec = "null"; /* passthrough (dummy) filter for video */
        else
            filter_spec = "anull"; /* passthrough (dummy) filter for audio */

        ret = init_filter(&filter_ctx[i], decode_ctx, encode_ctx, filter_spec);
        if (ret)
            return ret;

        filter_ctx[i].enc_pkt = av_packet_alloc();
        if (!filter_ctx[i].enc_pkt)
            return AVERROR(ENOMEM);

        filter_ctx[i].filtered_frame = av_frame_alloc();
        if (!filter_ctx[i].filtered_frame)
            return AVERROR(ENOMEM);
    }
    return 0;
}

int Transcode::encode_write_frame(unsigned int stream_index, int flush)
{
    StreamContext* stream = &stream_ctx[stream_index];
    FilteringContext* filter = &filter_ctx[stream_index];
    AVFrame* filt_frame = flush ? NULL : filter->filtered_frame;
    AVPacket* enc_pkt = filter->enc_pkt;
    int ret;

    av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
    /* encode filtered frame */
    av_packet_unref(enc_pkt);

    ret = avcodec_send_frame(stream->enc_ctx, filt_frame);

    if (ret < 0)
        return ret;

    while (ret >= 0) {
        ret = avcodec_receive_packet(stream->enc_ctx, enc_pkt);

        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
            return 0;

        /* prepare packet for muxing */
        enc_pkt->stream_index = stream_index;
        av_packet_rescale_ts(enc_pkt,
            stream->enc_ctx->time_base,
            ofmt_ctx->streams[stream_index]->time_base);

        av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
        /* mux encoded frame */
        ret = av_interleaved_write_frame(ofmt_ctx, enc_pkt);
    }

    return ret;
}

int Transcode::filter_encode_write_frame(AVFrame* frame, unsigned int stream_index)
{
    FilteringContext* filter = &filter_ctx[stream_index];
    int ret;

    av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
    /* push the decoded frame into the filtergraph */
    ret = av_buffersrc_add_frame_flags(filter->buffersrc_ctx,
        frame, 0);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
        return ret;
    }

    /* pull filtered frames from the filtergraph */
    while (1) {
        av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
        ret = av_buffersink_get_frame(filter->buffersink_ctx,
            filter->filtered_frame);
        if (ret < 0) {
            /* if no more frames for output - returns AVERROR(EAGAIN)
             * if flushed and no more frames for output - returns AVERROR_EOF
             * rewrite retcode to 0 to show it as normal procedure completion
             */
            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                ret = 0;
            break;
        }

        filter->filtered_frame->pict_type = AV_PICTURE_TYPE_NONE;
        ret = encode_write_frame(stream_index, 0);
        av_frame_unref(filter->filtered_frame);
        if (ret < 0)
            break;
    }
    return ret;
}

int Transcode::flush_encoder(unsigned int stream_index)
{
    if (!(stream_ctx[stream_index].enc_ctx->codec->capabilities &
        AV_CODEC_CAP_DELAY))
        return 0;

    av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
    return encode_write_frame(stream_index, 1);
}

void Transcode::clear_up(){
    for (unsigned int i = 0; ifmt_ctx && i < ifmt_ctx->nb_streams; i++) {
        avcodec_free_context(&stream_ctx[i].dec_ctx);
        if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && stream_ctx[i].enc_ctx)
            avcodec_free_context(&stream_ctx[i].enc_ctx);
        if (filter_ctx && filter_ctx[i].filter_graph) {
            avfilter_graph_free(&filter_ctx[i].filter_graph);
            av_packet_free(&filter_ctx[i].enc_pkt);
            av_frame_free(&filter_ctx[i].filtered_frame);
        }
        av_frame_free(&stream_ctx[i].dec_frame);
    }
    if(filter_ctx)
        av_free(filter_ctx);
    if(stream_ctx)
        av_free(stream_ctx);
    avformat_close_input(&ifmt_ctx);
    if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
        avio_closep(&ofmt_ctx->pb);
    avformat_free_context(ofmt_ctx);
}

bool parse_commandline(int argc, char** argv,Commondpara* para) {
    int oc;                     /*选项字符 */
    char* b_opt_arg;            /*选项参数字符串 */
    bool input_setted = false;
    bool output_setted = false;
    opterr = 0;
    //在调用getopt()之前，将opterr设置为0，这样就可以在getopt()函数发现错误的时候强制它不输出任何消息。
    char optstring[] = ":i:o:c::vh:w:r:";
    while ((oc = getopt(argc, argv, optstring)) != -1)
    {
        switch (oc)
        {
        case 'i':
        {
            b_opt_arg = optarg;
            strcpy(para->input_file, b_opt_arg);
            input_setted = true;
            printf("input file: %s.\n", b_opt_arg);
        }
        break;
        case 'o':
        {
            b_opt_arg = optarg;
            strcpy(para->output_file, b_opt_arg);
            output_setted = true;
            printf("output file: %s.\n", b_opt_arg);
        }
        break;
        case 'c':
        {
            b_opt_arg = optarg;
            printf("codec id: %s.\n", b_opt_arg);
            if (b_opt_arg != NULL) {
                int codecid = 0;
                if (sscanf(b_opt_arg, "%d", &codecid) != 1)
                    printf("codec id must be a int value.\n", b_opt_arg);
                else if (codecid == 97) {//AV_CODEC_ID_GIF
                    para->vcodec = (AVCodecID)codecid;
                    para->video_only = true;
                }
                else {
                    printf("Unsupported custom vodec.\n", b_opt_arg);
                    para->vcodec = AV_CODEC_ID_NONE;
                }
            }
        }
        break;
        case 'v':
        {
            para->video_only = true;
            printf("only video stream will be processed.\n");
        }
        break;
        case 'w':
        {
            b_opt_arg = optarg;
            int wid = 0;
            if (sscanf(b_opt_arg, "%d", &wid) == 1)
                para->video_width = wid;
            printf("width is: %d.\n", wid);
        }
        break;
        case 'h':
        {
            b_opt_arg = optarg;
            int hig = 0;
            if (sscanf(b_opt_arg, "%d", &hig) == 1)
                para->video_height = hig;
            printf("height is: %d.\n", hig);
        }
        break;
        case 'r':
        {
            b_opt_arg = optarg;
            int rate = 0;
            if (sscanf(b_opt_arg, "%d", &rate) == 1)
                para->video_frame_rate = rate;
            printf("rate is: %d.\n", rate);
        }
        break;
        case '?':
        {
            char ec = (char)optopt;
            printf("无效的选项字符 \' %c \'!\n", ec);
        }
        break;
        case ':':
            printf("缺少选项参数！\n");
            break;
        }
    }
    return input_setted && output_setted;
}

int transcode(int argc, char** argv)
{
    int ret;

    Transcode video2video;
    Commondpara para;
    if (parse_commandline(argc, argv,&para)) {
        av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
        return 1;
    }
    memcpy(&video2video.parameters,&para,sizeof(Commondpara));

    if ((ret = video2video.open_input_file(para.input_file)) < 0)
        goto end;
    if ((ret = video2video.open_output_file(para.output_file)) < 0)
        goto end;
    if ((ret = video2video.init_filters()) < 0)
        goto end;

    AVPacket* packet = NULL;
    if (!(packet = av_packet_alloc()))
        goto end;

    /* read all packets */
    unsigned int stream_index;
    while (1) {
        if ((ret = av_read_frame(video2video.ifmt_ctx, packet)) < 0)
            break;
        stream_index = packet->stream_index;
        if (video2video.parameters.video_only &&stream_index != video2video.v_stream_index)
            continue;
        av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
            stream_index);

        if (video2video.filter_ctx[stream_index].filter_graph) {
            StreamContext* stream = &(video2video.stream_ctx[stream_index]);

            av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");

            av_packet_rescale_ts(packet,
                video2video.ifmt_ctx->streams[stream_index]->time_base,
                stream->dec_ctx->time_base);
            ret = avcodec_send_packet(stream->dec_ctx, packet);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
                break;
            }

            while (ret >= 0) {
                ret = avcodec_receive_frame(stream->dec_ctx, stream->dec_frame);
                if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))
                    break;
                else if (ret < 0)
                    goto end;

                stream->dec_frame->pts = stream->dec_frame->best_effort_timestamp;
                ret = video2video.filter_encode_write_frame(stream->dec_frame, stream_index);
                if (ret < 0)
                    goto end;
            }
        }
        else {
            /* remux this frame without reencoding *///只是换封装而不用转码
            av_packet_rescale_ts(packet,
                video2video.ifmt_ctx->streams[stream_index]->time_base,
                video2video.ofmt_ctx->streams[stream_index]->time_base);

            ret = av_interleaved_write_frame(video2video.ofmt_ctx, packet);
            if (ret < 0)
                goto end;
        }
        av_packet_unref(packet);
    }

    /* flush filters and encoders */
    for (unsigned int i = 0; i < video2video.ifmt_ctx->nb_streams; i++) {
        /* flush filter */
        if (!video2video.filter_ctx[i].filter_graph)
            continue;
        ret = video2video.filter_encode_write_frame(NULL, i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
            goto end;
        }

        /* flush encoder */
        ret = video2video.flush_encoder(i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
            goto end;
        }
    }

    av_write_trailer(video2video.ofmt_ctx);
end:
    av_packet_free(&packet);
    video2video.clear_up();
    if (ret < 0) {
        char error_buf[64] = { 0 };
        av_make_error_string(error_buf, 64, ret);
        av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", error_buf);
    }
    return ret ? 1 : 0;
}
